Tinea, what is called athlete's foot, is dermatomycosis caused by infection of the skin with dermatophytes such as Tricophyton rubrum (hereinafter to be abbreviated as T. rubrum), Tricophyton mentagrophytes (hereinafter to be abbreviated as T. mentagrophytes), Microsporum canis (hereinafter to be abbreviated as M. canis), Epidermophyton floccosum (hereinafter to be abbreviated as E. floccosum) and the like. The main fungal infection site is interdigit of foot. However, genital, corpus and the like are also infected therewith, causing inflammation and intense pruritus in the infection site.
The diagnosis of tinea is mainly based on potassium hydroxide (KOH) direct microscopic examination including dissolving cornified layer obtained from the patient's skin with KOH and heat treatment, and microscopically observing hyphae. The microscopic examination requires considerable training, where difference between hypha and dust may be misjudged. While fungus itself can also be cultured and examined, it takes substantial time before the results are obtained.
It is often difficult to distinguish tinea from other diseases requiring different treatment methods such as eczema, dermatitis, pompholyx and the like. In fact, there is a report indicating that one-third of patients who visit dermatologists for “athlete's foot” as the chief complaint is affected with different diseases. Due to treatments based on such erroneous self-judgment, inflammation is frequently prolonged and may not cure.
As a detection method of athlete's foot, a dermatophyte infection site detection method using a copper sulfate solution is reported (see patent reference 1). This method enables detection in a short time at a low cost. However, as far as the present inventors have studied, no significant difference was found between healthy subjects and carrier subjects of tinea unguium.
The present inventor has produced an antibody against various tinea fungi (dermatophyte) antigens, found a method of specifically detecting tinea fungi (see patent references 2 and 3), whereby enabling convenient diagnosis of tinea fungi infection. However, since the method requires a heat treatment step irrespective of whether an enzyme treatment is involved, the detection is not always possible at any place. In addition, the method has a risk of burn and the like due to heating, posing a safety problem.
Accordingly, there is a demand for a convenient detection method of tinea fungi that does not require a complicated operation such as a heat treatment and the like.    patent reference 1: JP-A-2001-187750    patent reference 2: JP-A-2004-159593    patent reference 3: JP-A-2004-258024